Identification of Psychological Correlates of Dietary Mis-Reporting under Laboratory and Free-Living Environments

Errors inherent in self-reported measures of energy intake (EI) are substantial and well-documented, but correlates of mis-reporting remain unclear. Therefore, potential predictors of mis-reporting were examined. In Study One, 59 individuals (BMI=26.1±3.8kg/m2, age=42.7±13.6yrs, females=29) completed a 14d stay in a residential feeding behaviour suite where eating behaviour was continuously monitored. In Study Two, 182 individuals (BMI=25.7±3.9kg/m2, age=42.4±12.2yrs, females=96) completed two consecutive days in a residential feeding suite and five consecutive days at home. Mis-reporting was directly quantified by comparing covertly measured laboratory weighed intakes (LWI) to self-reported EI (weighed dietary record; WDR, 24-hr recall, 7-day diet history, food frequency questionnaire; FFQ). Personal (age, sex, %body fat) and psychological traits (personality, social desirability, body image, IQ, eating behaviour) were used as predictors of mis-reporting. In Study One, those with lower psychoticism (p=0.009), openness to experience (p=0.006) and higher agreeableness (p=0.038) reduced EI on days participants knew EI was being measured to a greater extent than on covert days. Isolated associations existed between personality traits (psychoticism, openness to experience), eating behaviour (emotional eating) and differences between the LWI and self-reported EIs, but these were inconsistent between dietary assessment techniques and typically became non-significant after accounting for multiplicity of comparisons. In Study Two, sex was associated with differences between LWI and the WDR (p=0.009), 24-hr recall (p=0.002) and diet history (p=0.050) in the laboratory, but not home environment. Personal and psychological correlates of mis-reporting identified displayed no clear pattern across studies or dietary assessment techniques, and had little utility in predicting mis-reporting.